Contour duplicating apparatus



Aug. 13, 1953 M. SHARP CONTOUR DUPLICATING APPARATUS 3 Sheets-Sheet 1 Filed Feb. 8. 1960 INVENTOR. MARTIN SHARP BY/fgww/ ATTORNEY Aug. 13, 1963 M SHARP CONTOUR DUPLICATING APPARATUS 5 Sheets-Sheet 2 Filed Feb. 8. 1960 ATTORNEY Aug. 13, 1963 M. SHARP CONTOUR DUPLICATING APPARATUS 3 Sheets-Sheet 5 Filed Feb. 8, 1960 vw c.. \X MT. vh ow NW QM mv r ...l .INM

INVENTOR. MARTIN SHARP l BVM ATTORNEY Y 3,100,344 CONTUR DUPMCAHNG APPARATUS Martin Sharp, 7906 Chandler Road, Philadelphia, la. Filed Feb. 8, 1960, Ser. No. 7,370 Claims. (Cl. 32-67) This invention relates to dental apparatus, and more particularly to dental apparatus for making inlays Vfor insertion into one or more teeth of a patient, or for preparing the teeth for mouth rehabilitation, such as bridge abutments. The apparatus according .to this invention is an improvement over the apparatus described in my co-pending application :for United States Letters Patent, Serial No. 756,847, tiled August 25, 1958, now Patent No. 3,037,283. While the broad overall concept of the instant land co-peuding applications are the same, the apparatus to be described in this application represents a structural improvement achieved by the incorporation of several novel features resulting in a less expensive, more compact, and more easily manipulated unit.

In the past, the practice has been to take a set of X-rays of the patients mouth and, -in accordance with the information revealed, to then drill out various portions of the teeth for which the inlays are to be made. Impressions of the drilled out tooth areas are then taken, from which the inlay is made. Since some time is required in order to cast or :otherwise form the inlays, temporary fillings .are placed in the pat-ientis teeth so that normal mouth rfunctions will not be interfered with unduly until such time as .the inlays themselves may be fitted into the teeth. When the inlays are ready, the patient must then return to the dentist and have the temporary lillings removed so that the inlays may be placed in the teeth. If any extensive amount `of inlay work is required, -for example work involving `a large number of teeth, it is Ithe usual practice to drill only a .few teeth at a time and to make the inlays for these teeth, before proceeding to further inlay work on other teeth. As `a consequence, a number of visits to the dentist are generally required and can entail a great loss of time to the patient from his normal schedule of activity, `such lost time frequently representing an'appreciable amount of inconvenience.

By the use of the apparatus according to my invention, it is generally .possible to limit the required number of visits t0 the dentist to only two. On the iirst Visit, the dentist takes a set of mouth X-rays and also an impression of the upper and/or lower set of teeth in the patients mouth. At :this time, no drilling of the patients teeth whatever is done so that the normal mouth functions remain completely intact and the discomfort and annoyance of tempormily filled teeth is eliminated. 'From the mouth casts the dentist may construct a model, and the teeth of the model may then be drilled out according to the information revealed by the X-rays. From the drilled-out teeth of the model, and the inlays themselves may be prepared. Upon the return of the patient to the dentist, the patients teeth may lbe drilled in .exact conformance with the drillings in the model, and hence the inlays prepared from the model will lit precisely into the patients teeth and may be installed as soon as any given tooth has been so drilled. It will be appreciated that the precision of it of the inlay into the teeth of a patient is much greater when the necessity of removing a temporary filling is avoided. This is because such removal entails further dental drilling and the drilling of necessity, at least somewhat, changes the shape of the inlay cavity and, therefore, a perfect fit with an inlay made from an impression cannot be obtained. Accordingly, itis a primary object of my invention to provide novel dental apparatus for performing dental inlay work which does not -require that a patient be subjected to a double drilling of his teeth 'by eliminating the necessity for using temporary fillings,

t system.

Another object of my invention is to provide novel dental apparatus -for peforming ldenta-l inlay work by which a near .perfect ht between `an inlay and the drilled out cavity of the inlay receiving tooth may be achieved.

Still another object of my invention is to provide novel den-tal inlay .apparatus the use of 'which substantially reduces the required number of visits to the dentists oiice by a patient.

Yet another object of my invention is to provide novel dental inlay work which does not require that a patient be results, and effects a monetary saving to both the patient and the dentist by enabling the saving of .a substantial amount of time as compared to that required for the carrying out of inlay work by presently used methods.

'These and other objects will .become clear from a careful reading of the following specification when taken in conjunction with the Iseveral drawings, wherein:

FIGURE l is a plan view of the apparatus according to th invention .illustrating the `drilling out of the teeth of the patient in accordance with the model made from the patients mouth;

FIGURE 2 is a side elevational View of the apparatus yof FIGURE 1 taken along the lines 2-2 of that lign-re;

FIGURE 3 is a sectional view taken along the lines 3--3 of -FIGURE 2 and showing certain pivot and carriage details of .the apparatus;

FIGURE 4 is a fragmentaryv sectional view taken along the lines -4-4 of AFIGURE 3 `and illustrates the structure for lachieving drill rotation about .the drill handle lon-g axis;

LFIGURE 5 is a central sectional View taken through the carriage structure yas would be seen when viewed .along the lines `5--5 of 'FIGURE l;

lFIGURE 6 is a rear elevation of the apparatus as would be seen when viewed along the lines 6-6 of PIG- URE 5.

In the .several figures, like elements are denoted by like reference numerals.

Referring now to the figures and firstly to FIGURE l,

it will be seen that the apparatus laccording to my invention consists essentially of three functional Iunits, a supporting stand'or mount 2t), .a carriage 21,1and a unity ratio pantograph including four arms 22, 23, 24 and 24', connected to the carriage 2l by a two dimensional pivot Fixedly secured to the right-hand side of the ,stand ormount k2li by a -pair of screws -25 is a model 26 of `a set of lower teeth of a patients mouth. Some Vof the teeth, .as 4for example the teeth 27, 28 and 29, have been drilled Iout in accordance with infomation obtained from a set of X-rays, and impressions taken the drilled out teeth of the model have been used to make a set of inlays to be inserted in :the A,corresponding teeth in the patients mouth; i

Immediately tothe left of the dental model 26 is seen a portion of the lower jaw of the patient from which the model 26 was made, so that the set of lower teeth shown therein conform exactly in size, shape and relative position to t-he teeth of the model 26. The teeth 27', 28', and 29 in the patients jaw correspond therefore to the teeth 27, 28 and 29 in the dental model 26. It is the function of the dental apparatus illustratedto enable the dentist to drill the teeth 27', 28 and y29 inexact conformance with the drillintgs of the con. responding teeth in the dental model 26, and hence provide perfect receptacles for the inlays made Kfrom the impressions taken from the drilled teeth of the dental model. In order that the drillings Iof teeth 27', 28

. and 29' shall be in exact conformance with the drillings One possible clamping system is illustrated in FIG- URES l,V and 6 and includes a chin rest 3Q (illustrated in FIGURE 5) secured to the mount 2d* by a braclet 3l and a pair of machine screws 32. Additionally provided is a jaw clamp including a'lgenerally T-shaped center sup- -port having a pair of laterally opposite extending fixed arms 34 and a central depending stem portion 3S, the 'stem portion ofthe clamp central support being lfixed v.upon the mount by the machine screw 33. EachV ofthe center support lixed arms 34 is horizontally slotted at its extremity to receive the broad end of a horizontally swingable clamparm 36 pivotallyvsecured within the* slots by means lof the pins 37. v 'Both` of the swingable clamp arms 36 are provided with a plurality of longitudinally spaced key holes 38 by means of which the crevcent: shaped hooks 39 maybe detachably secured thereto at a desired position along the arm length by extending downwand therethrough theV stud 40 which projects from theundersurface of the hooks 39.

A shaft 41 is threaded through the T-shaped center support Vand has swivelly secured to its forward end a Vwedgeftz adapted Ito be brought into engagement with the central incisors as the shaft is rotatably advanced by of rigid plate members 66 and 67 into which opposite ends of the lower cylindrical shaft 60 are firmly set, as for example by shrinlr fitting, so that the carriage 21 is rigidly secured to both of theV shafts S9 and'tl. This ball bearing mounted double shaft arrangement eliminates any tendency toward rotational play of the carriage 21 in a verticalplane.

As best seen in FIGURES 1, 3 and 6, and particularly in the showing of FIGURES, each of the arm ends means of the knob 43 secured to its rearward end.v By

Vturning theknob 43, the -jaw is shifted rearward so as .to lock the hooks 39 behind the rear `molars and effect jaw, clamping. The absence of a rear molar may be omp'ensatedfor by moving the appropriate hook 39 for- "war-d for secu-rement within a dierent keyhole 3S. g For ka more ,detailed description IofV this jaw clamping ap-v paratus' reference may behad to my co-pending applica# ,tionvfor United States Letters Patent, Serial No. 3,178,

- mentv of which is `shown in FIGURE Srsecured to the "mount20 by the machine screw 45, may be clamped to the dental chair so that'the latter supports the weight ofthe apparatus andy carries it along with the `dental ychair whenrany chair motion occurs.

,Turning-'now' to a consideration of 'the carriage 21 f which carries theunity ratio pantograph, and the means by which the carriage is supported upon `the mount 20, as best seen in FIGURE 5 a vertical post' 54 is secured `fupon the mount 20 by'means of the machine screw 55 which-.passes through a hole 'drilled in the mounting within a pairfof holes extending from vfront `to'iback through the post54 and `spaced one above the other are a pair of ball bearing assemblies 56 andv 57 secured there- Vwithinfby means of the C-washers 58. Disposed within 56 and 57l area pair' of cylindricalshafts S9 vand 60 to which the carriage 21 is secured and by means which the entire carriage land pantograph'assernbly is smoothly 'and -easily shiftable fore and aft in a horizontal plane.

oriented generally C-shaped member 6lv the arms of .which extend rearwandly andlaterally outwardly, the

:arin ends 62 turning int'o parallel relationship with one vanother-'and theaxes of the cylindrical shafts 59 and 60. Secured, to the intermediate portions of the arms of the Vfrom in parallel relationshipon opposite sides. ofthe post 54 are a pair of bracket members 63 secured at their rear ends by means of a tieplatel64. .The upper carriage shaft 591is recessed into theV tie plate 64 at the Yrear of the carriage and also into the central region of the;

G-shaped member `61 at the fore endof the carriage' and non-rotatably secured by means of the vertically extendirigpins 65. Secured at opposite ends of the carriage 21 and extending vertically downward therefrom are aY pair 62 of the C-shaped member 61 is fitted with a'ball bearing assembly 68 which rotatably supports one end of a shaft e9, the other end of each Yof 'the shafts 69 being rotatably journalled in the ball bearing assemblies 70 fitted into the bracket members V63. Fixedly secured to and rotatable with each of the rotatable shafts 69 is an angle bracket 7l which extends laterally outward beyond the main frame-of the carriage 21 for pivotal seourement respectively with the pantograph arms 22 and 23. The bearinegmounted shafts 69 and associated angle members 71 allow for rotational motion of the pentograph arms in a Ivertical plane. As also best seen in the showing of FIGURE 3, `the outer extremities of the angle membersl` are pivotally connected to the underside of the pantograph arms 22 and 23 :by means of the ball bearing Y assemblies 72 so that the pantograph arms 22 and 23 are free to pivot laterally in planes parallel to the axis ,of the co-axial rotatable shafts 69.

Disposed toward the rear ends of the pantograph arms i [22 and 23 and bridging therebetween is the pantograph arm 244 pivotally secured atfopposite ends to the undersurface of the pantograph arms 22 and 23 respectively as i The spacing between the ball .hearing assemblies 72 and 73 on'each of Vthe arms 22 and 23 is identically the same, and the lateral Vspacing 'between the ball bearing assemblies 72 at the 'fore end of the pantograph arms 22 and 23 is the` same as the lateral spacing between the ball bearing assemblies 73 located at'the rear of the arms Y fp1ate'20 and Aupward into a threaded Vbore extending upvwardly into the post 54 from the bottom thereof.V Seated 22V and 23, so that the pantograph is a unity ratio ldevice. l Y

The function of the pantograph includ-ing the arms 22,

23,' -24and 24' is to enable a dental drill S, secured to Vwhichy traces the inside surface of the cavities drilled in the teeth ofthe dental model 26. As shown in FIGURES l and.2 the pin 51 is vpositioned within the inlay cavity of the tooth 2-8. The position of the feeler pin 51 controls i the position of the drill bit 52 mounted at the fore'end of the drill 50, and since the pantograph is designed for v rvand extending fore and aft 'of the balllbearing assemblies v Y In thisrway, it can be seen that as the feeler pin 51 traces f' As best seen in the showingof ililGUrRl-l 1, the car- -riasge4 21 has a main frame which includes a horizontally 60 V "C-shaped member `61 and extending rearwardly there- :unity arm rat-io, a given displacement of the feeler pin 51 always causes an identical displacement of the drill bit 52.

out the outline and depth of the cavity infor example the tooth 28, the drill bit 52 will drill an identical cavity in the tooth 28 of the patients mouth.

The previously described pivoting arrangements which interconnect the pantograph arms 22, 23 and 24 and the carriagell, together with the mechanical coupling system involving the arm 24', still to be described, allows for .three-dimensional rotation together with the longitudinal Vshifting of the carriage 21 is required in order to accunately follow the surface of the inlay cavity drilled in the f teeth of the dental model 26. The structure for securing the dental drill 5d and tracing arm l53 to the pantograph a arms22'and 23 in a manner which allows for rotation of the drill 50 and tracing arm 'S3 about their long axes will vnow be described, principally in connection with the showings of FIGURESVI, 4 and 6.

Each of the pantograph arms 22 and 23 has formed at its fore end a hollow cylindrical formation 74 and at its rear end a hollow Ycylindrical formation 75, the formations 74 and 75 of each of the pantograph arms `22 and 23 being co-axially aligned and open at both ends. Rotatably disposed within each of the hollow cylindrical formations 74 and 75 is a hollow sleeve 76 having an enlarged diameter end 77 which abuts one end of the associated hollow cylindrical formations 74 or 75. Passing through the hollow sleeves 76 of the pantograph arm 22 is the barrel of the drill hand piece 5l) and passing through the hollow sleeves 76 of the pantograph arm 23- is the barrel of the tracing arm 53. Each of the hollow sleeves 75 is non-rotatably secured to its associated drill hand piece -50 or tracing arm 53 by means of the set screws 78 which pass through the enlarged end 77 of each of the hollow sleeves.

With the hollow sleeves 76 secured to the drill 50 and tracing arm 53 as best seen in the showing of FIGURE l, it is observed that the enlarged ends 77 of the hollow sleeves 76 labut the hollow cylindrical formations 74 of the pantograph arms 22 and 23 at the fore ends thereof and thus prevent the drill hand piece 50 and tracing arm 53 from rear-ward shifting relative to the pantograph arms. Similarly, the enlarged ends 77 of the hollow sleeves 7-6 which abut the hollow cylindrical formations 7S of the pantograph arms 22 and 23 prevent the drill hand piece 50 and tracing arm 53 from forward shifting relative to the pantograph arms. Thus, the drill hand piece 50 and tracing arm 53 have only one degree of freedom, which is that of rotation on their long axes, the sleeves 76 secured thereto rotating smoothly .within the pantograph arms hollow cylindrical formations 74 and 75. in order to couple the rotational motion of the tracing arm 53 to the drill hand piece 50, the interconnecting arm 24 is employed.

As best seen in the showing of FIGURE 6, the enlarged ends 77 of the hollow sleeves 76 disposed at the rear of the pantograph include a rigidly laiiixed depending pin 7 9 which latter terminates at its lower extremity in a ball 80u Each of the balls 80 is disposed within a conforming socket formed a-t opposite ends cf the arm 24 so that the balls 80 are free to rotate easily therewithin. Thus, as the tracing arm 53 is axially rotated the rear sleeve `76 rotates lwith it and causes the associated ball 80 to shift laterally to the left or the right, 4thus shifting the arm 214 and transmitting this motion to the ball 80 and pin 79 associated with the sleeve 76 clamped to the drill hand piece 50. The drill hand piece 50; of cofurse, is thereby caused to rotate axially in conformance with the rotation of the hand piece 53.

Although the invention has been described in connection with a particularly -illustrated embodiment showing the application thereof to the field of dentistry, i-t should be understood that the invention is not so limited, and in fact, has a wide range of application in other fields and for other purposes. IFor example, the apparatus according to the invention might well be used for the duplication of precision parts to be used in structures not related to the dental iield, such as machine parts. Such a use would be very time saving as compared to the time required by a machinist to make a particularly configured part in conformance with a set of blue prints, and'would be well adaptable to the manufacture of relatively complicated shapes by persons not trained to read complicated blueprints or diagrams and not having experience with the use of a wide range of machine tools. Accordingly, labor costs associated with the production of articles heretofore requiring highly skilled machinists could be markedly reduced.

Although my invention has been described in connection with a particularly illustrated apparatus for practicing the same, it -will be understood that such description is for illustrative purposes only, and various changes and modifications may Ibe made from time to time without departing from the general principles or real spirit thereof and it is intended to claim the same broadly as well as specifically as indicated by the appended claims.

What is claimed as new and useful is:

1. Contour duplicating apparatus comprising a stand, a carriage mounted on said stand and translationally shiftable relative to the latter, a pantograph having arms pivotally mounted to said carriage for translation therewith and rotation relative thereto, a cutting tool, a sensing element, first means carried by said pantograph arms rotat'ably securing thereto said cutting tool and said sensing element in spaced relationship, and second means so intercoupling the cutting tool and sensing element that rotational motions of the sensing element relative to said pantograph produce corresponding rota-tional motions of the cutting tool.

2. The appanatus according to claim l wherein said first means comprises a plurality of pairs of coaxial sleeves, one sleeve of each pair being closely iitted within the other for rotation relative thereto about the common axis, the outer sleeve of at least a iirst one of said coaxial sleeve pairs being iixedly secured to one arm of said pantograph and the outer sleeve of at least a second of said pairs being iixedly secured to another of said pantograph arms, the inner sleeve of said iirst pair including means iixedly securing it to said cutting tool, and the inner sleeve of said second pair including means fixedly securing it to said sensing element.

3. The apparatus according to claim 2 wherein the inner sleeve of each coaxial pair includes an enlarged diameter end located externally to and in abutment wit the end of the associated outer sleeve whereby relative axial shifting between said sleeves is possible in only one direction at most.

4. The apparatus according to claim 2 wherein said second means includes an arm having a ball joint at opposite ends thereof, one ball joint being iixedly connected to the inner sleeve of said first coaxial pair and the other ball joint being fixedly connected to the inner sleeve of said second coaxial pair.

`5. The apparatus according to claim l wherein said first means comprises a plurality of pairs of coaxial members, a vfirst member of each pair being closely fitted wit-hin the second for rotation relative thereto about the common axis, one member of at least two of such pairs being xedly secured respectively to dilferent arms of said pantograph, the unsecured member of one of said at least two pairs including'means ixedly securing it to said cutting tool, and the unsecured member-of the other of said at least two pairs including means iixedly securing it to said sensing element.

6. The apparatus according to claim 5 wherein one member of each coaxial pair includes means for restricting axial shifting thereof relative to the cther'member of the pair to one direction at most.

7. The apparatus according to claim 1 wherein said stand includes a vertical post member supporting in vertically spaced parallel relation a pair of open-ended bearings, said carriage includes a pair of vertically spaced parallel extending horizontal shafts ixedly secured thereto at opposite ends, and said carriage shafts are disposed within said postl bearings for rectilinear shifting therethrough.

8. The apparatusV according to claim l wherein said carriage includes a main frame tixedly secured to a horizlontally extending shaft, said shaft being disposed within and extending outwardly beyond the open ends of a stand carried bearing which supports said shaft for rectilinear shifting in a horizontal plane.

9. Contour duplicating apparatus comprising a stand, a carriage mounted on said stand and translationally shiftable relative to said stand, a pantograph pivotally mounted to said carriage for translation therewith and rotation relative thereto, and means carried by said panto- *to` said pantograph produce tions of thecutting tool.

l0. :Contour duplicating apparatus comprising a stand, a carriage mountedon said stand and translationally shiftable relative to the latten/'a pantograph'having arms pivotallymounted to said carriage for translation therewith and rotation reiative thereto, rs means carried by said pantograph arms for rotatably securing thereto a cutting tool and a sensing element in spaced relation- Y Y f ship,V and second means for so intercoupling the cutting tool and'sensing element when they are so secured by said first means that rotational motions of the sensing corresponding rotational mon element relative to said pantograph produce corresponding rotational motions of the cutting tool, said first and second means being themselves at ieast partially intercoupled and the inter-coupled parts beingdetachable from said pantograph arms. 1

References Cited in the le of this patent UNITED STATES PATENTS 1,472,034 Asquith Oct. 30, 1923 2,793,569 Tanner et al. May 28, 1957 2,817,901 Freeman Dec. 31, 1957 

1. CONTOUR DUPLICATING APPARATUS COMPRISING A STAND, A CARRIAGE MOUNTED ON SAID STAND AND TRANSLATIONALLY SHIFTABLE RELATIVE TO THE LATTER, A PANTOGRAPH HAVING ARMS PIVOTALLY MOUNTED TO SAID CARRIAGE FOR TRANSLATION THEREWITH AND ROTATION RELATIVE THERETO, A CUTTING TOOL, A SENSING ELEMENT, FIRST MEANS CARRIED BY SAID PANTOGRAPH ARMS ROTATABLY SECURING THERETO SAID CUTTING TOOL AND SAID SENSING ELEMENT IN SPACED RELATIONSHIP, AND SECOND MEANS SO INTERCOUPLING THE CUTTING TOOL AND SENSING ELEMENT THAT ROTATIONAL MOTIONS OF THE SENSING ELEMENT RELATIVE TO SAID 